Method and apparatus for insulating

ABSTRACT

A heat-insulating assembly (10) for insulating a surface of a tubular body (30) relative to the ambient air comprises a length of an annular heat-insulating body (12, 14) defining an inner cylindrical surface (17) and an outer cylindrical surface (16). A vapor-barrier layer is applied to and covers the outer cylindrical surface of the annular heat-insulating body. A through-going slit (11, 15) extends through the annular heat-insulating body (12, 14) in the entire length thereof for allowing the annular heat-insulating body (12-14) to be opened for positioning the annular heat-insulating body (10) circumferentially encircling the tubular body (30) so as to position the inner cylindrical surface (17) juxtaposed the surface of the tubular body (30). A strip (24) of a water transport-allowing material is further provided defining a width substantially smaller than the length of the annular heat-insulating body (10) and a length allowing the strip (24) to be arranged within the annular heat-insulating body (10) circumferentially encircling the tubular body (30) and extending through the slit (11, 15) of the annular heat-insulating body for presenting an exposed flap (26) of the strip (24) at the outer cylindrical surface (16) of the annular heat-insulating body (10) to be exposed to the ambient air for the evaporation of water transferred from the surface of the tubular body (30) to the flap (26) of the strip (24) through the strip.

The present invention relates to the technical field of insulation. Moreprecisely, the present invention relates to a technique involvinginsulating a surface of a tubular body by means of a heat-insulatingbody or layer which tubular body is exposed to accumulating condensedwater such as a pipe having a surface temperature at or below the dewpoint of the ambient air.

In numerous applications, a body is kept at a temperature at or belowthe dew point of the ambient air, which body may e.g. constitute a pipeof a freezing or refrigerator system or of an air-conditioning system,or a pipe supplying cold water. Alternatively, the body may e.g.constitute a structure of a building which is exposed to a lowtemperature from the environment, whereas, in the present context, theambient air refers to the heated air of the building, which ambient airis typically heated to a temperature above the temperature of theenvironment. The ambient air also contains an increased amount ofmoisture as compared to the environment. Furthermore, it has beenrealized that even heat-insulating layers of pipes conducting heatedwater may in some instances be exposed to accumulating water asdescribed in an article in the Norwegian magazine "Kulde" No. 5, October1993, including a special issue relating to the technical field:"Teknisk Isolation" or in English language: "Technical insulatingtechnique", page 4-6. According to the realization described in theabove magazine, pipes normally conducting heated water or even steammay, provided the pipes are covered by an insulating layer and providingthe pipe and the insulating layer are exposed to the environment such asrain, snow, fog, etc., generate accumulation of condensed water withinthe insulating layer under certain conditions such as reduced flow ofhot water or steam through the pipe causing cooling of the pipe andexposure of the insulating layer to rain or snow. In the belowdescription, reference is, however, solely made to a body having asurface temperature at or below the dew point of the ambient air which,however, is by no means to be construed limiting the technical field ofthe present invention to insulating surfaces of bodies having surfacetemperatures at or below the dew point of the ambient air and excludingequivalent technical areas such as the above described pipes conductinghot water or steam which as described above, may also give origin to theaccumulation of condensed water within the heat-insulating layer of thepipes. The insulating layer may comprise mineral wool, such as glasswool, rock wool or slag wool, or may alternatively comprise foamedplastics or elastomeric materials, such as closed or open cells offoamed material, e.g. polyurethane foam, or may further alternativelycomprise combinations of the materials mentioned above.

Hitherto, it has been attempted to block transfer of moisture from theambient air to the body in question having a surface temperature at orbelow the dew point of the ambient air by providing a moisture-transferblocking foil, such as an aluminum or plastic foil, which serves toblock the diffusion of moisture into the insulating layer and furtherinto contact with the surface of the body having a surface temperatureat or below the dew point of the ambient air.

Various problems, however, occur, such as problems relating to foiljunctions and perforation of the foil constituting the moisture or watertransport-blocking barrier, and these problems in some instances, inparticular in connection with non-water repellent products or materials,result in moisture penetrating into the insulating layer and causinggeneration of condensed water at the surface of the body. The generationof condensed water at the surface of the body, firstly, results in areduction of the insulating property of the insulating layer, and may,secondly, cause corrosion and/or deterioration of the surface of thebody or of the body itself and/or of the insulating layer.

From international patent application No. PCT/DK91/00132, publicationNo. WO 91/18237, an insulating system for insulating e.g. a pipesupplying cold water is described including a condensed water drainingsystem. This insulating system is of an elaborated structure, whichrenders the insulating system complex and expensive. A serious drawbackrelating to the insulating system known from the above-mentionedinternational patent application relates to the fact that the insulatingsystem is extremely slowly responding to the generation of condensedwater at the surface of the body which is insulated by means of theinsulating system since the insulating system accumulates a fairly largeamount of condensed water before the draining system for draining thecondensed water becomes operative.

An object of the present invention is to provide a simple technique forremoving condensed water from a surface of a tubular body having asurface temperature at or below the dew point of the ambient air, whichtechnique, on the one hand, is swift responding to the presence ofcondensed water, and, on the other hand, is adaptable to specificapplication requirements, such as requirements relating to thewater-removal capacity requested, the moisture content of the ambientair, and further the temperature difference between the surfacetemperature of the body and the temperature of the ambient air.

A feature of the present invention is to provide a novel techniquerendering it possible to provide insulating systems from an integralheat-insulating assembly, still fulfilling specific requirementsrelating to the water-removal capability requested, the moisture contentof the air, and further the temperature difference between the surfacetemperature of the body and the temperature of the ambient air.

An advantage of the present invention is the fact that theheat-insulating assembly is readily and easily applicable for providingadequate and sufficient removal of condensed water from a tubular body,such as a pipe.

The above object, the above feature and the above advantage, togetherwith numerous other objects, advantages and features, which will beevident from the below detailed description of preferred embodiments ofthe device and the insulating assembly according to the presentinvention, are, in accordance with a first aspect of the presentinvention, obtained by means of a heat-insulating assembly forinsulating a surface of a tubular body relative to the ambient air,comprising:

a length of an annular heat-insulating body defining an innercylindrical surface and an outer cylindrical surface, a vapour-barrierlayer being applied to and covering the outer cylindrical surface of theannular heat-insulating body, and a through-going slit extending throughthe annular heat-insulating body in the entire length thereof so as toallow the annular heat-insulating body to be opened for positioning theannular heat-insulating body circumferentially encircling the tubularbody so as to position the inner cylindrical surface juxtaposed thesurface of the tubular body, and

a strip of a water transport-allowing material defining a widthsubstantially smaller than the length of the annular heat-insulatingbody and a length allowing the strip to be arranged within the annularheat-insulating body circumferentially encircling the tubular body andextending through the slit of the annular heat-insulating body forpresenting an exposed flap of the strip at the outer cylindrical surfaceof the annular heat-insulating body to be exposed to the ambient air forthe evaporation of water transferred from the surface of the tubularbody to the flap of the strip through the strip of the watertransport-allowing material.

According to the present invention, the strip of watertransport-allowing material is of a reduced size as compared to thedraining system of the insulating system described in the abovementioned international patent application. Thus, it has been realizedthat the draining of condensed water from the surface of the tubularbody which is insulated by means of an insulating layer such as anannular heat-insulating body is delayed until the watertransport-allowing material is entirely soaked with water. Therefore,provided a large amount of water transport-allowing material is used, afairly large amount of water has to be accumulated by the watertransport-allowing material before the condensed water draining effectoccurs. The accumulation of a fairly large amount of water within thewater transport-allowing material is of course less advantageous sincethe presence of a fairly large amount of condensed water may, firstly,deteriorate the material of the tubular body such as the pipe and,secondly, deteriorate the insulating material or reduce theheat-insulating properties of the heat-insulating materials.

In the present context, the expression "the water transport-allowingmaterial" means any material allowing the tranfer or transport of waterthrough the material from the surface of the tubular body, through theannular heat-insulating body and to the ambient air. Preferably, thematerial constituting the water transport-allowing material exibitcharacteristics promoting or accelerating the transfer of water throughcapillary action, through suction, through hygroscopic characteristicsof the material or any other action or through any other characteristicof the material having chemical or physical origin.

According to presently preferred embodiment of the heat-insulatingassembly according to the first aspect of the present invention, thewater transport-allowing material is preferably a capillary suctionmaterial rendering it possible to position the assembly according to thefirst aspect of the present invention in any arbitrary orientationrelative to the vertical orientation as the condensed water is removedfrom the surface of the body in question through capillary suctionirrespective of the gravitational force to which the condensed water isexposed.

The heat-insulating assembly according to the present invention may beproduced from any insulating material such as mineral wool, glass wool,rockwool or slack wool, foamed plastics material or elastomericmaterials, such as closed or open cells of foamed material, e.g.polyurethane foam, or even combinations of the above materials.Preferably, the annular heat-insulating body of the heat-insulatingassembly according to the present invention prefebly comprises mineralfibers and is preferably made from mineral fibers.

In order to prevent that vapour or water may permeate through the slitextending through the annular heat-insulating body, the heat-insulatingassembly according to the present invention preferably further comprisesa sealing means for sealing the through-going slit of the annularheat-insulating body. The sealing means may be constituted by e.g. alength of a vapour-impermeable adhesive tape such as an aluminum tapeprovided with an adhesive surface coating. Alternatively, according to aadvantageous embodiment of the heat-insulating assembly according to thepresent invention, the sealing means is constituted by a flap of thevapour barrier layer extending along the through-going slit of theannular heat-insulating body and has an adhesive coating for adhering tothe vapour-barrier layer in overlapping relationship therewith along thethrough-going slit of the annular heat-insulating body.

According to a further embodiment of the heat-insulating assemblyaccording to the present invention, the heat-insulating assemblycomprises a perforated foil of a vapour-barrier material to be appliedto the vapour-barrier layer covering the outer cylindrical surface ofthe annular heat-insulating body so as to expose the flap of the stripof the water transport-allowing material through perforations of theperforated foil. Alternatively, the flap of the strip exposed to theambient air may freely extend from the outer cylindrical surface of theannular heat-insulating body, provided no risk of mechanicallycontacting and destroying the flap exists.

In a further advantageous embodiment of the heat-insulating assemblyaccording to the present invention constituting an integral unitarystructure to be applied to the tubular body to be insulated by means ofthe heat-Insulating assembly, the strip defines opposite first andsecond ends, which first end is adhered to the annular heat-insulatingbody at the through-going slit of the annular heat-insulating body, andwhich second end defines the flap of the strip for the evaporation ofwater transferrred from the surface of the tubular body to the flap ofthe strip through the strip of the water transport-allowing material.

The above object, the above feature and the above advantage, togetherwith numerous other objects, advantages and features, which will beevident from the below detailed description of preferred embodiments ofthe present invention, are, in accordance with a second aspect of thepresent invention, provided by means of a method of insulating a surfaceof a tubular body relative to the ambient air and removing condencewater from the surface of the tubular body, comprising:

providing a heat-insulating assembly for insulating the surface of thetubular body, comprising:

a length of an annular heat-insulating body defining an innercylindrical surface and an outer cylindrical surface, a vapour-barrierlayer being applied to and covering the outer cylindrical surface of theannular heat-insulating body, and a through-going slit extending throughthe annular heat-insulating body in the entire length thereof so as toallow the annular heat-insulating body to be opened for positioning theannular heat-insulating body circumferentially encircling the tubularbody so as to position the inner cylindrical surface juxtaposed thesurface of the tubular body, and

a strip of a water transport-allowing material defining a widthsubstantially smaller than the length of the annular heat-insulatingbody and a length allowing the strip to be arranged within the annularheat-insulating body circumferentially encircling the tubular body andextending through the slit of the annular heat-insulating body forpresenting an exposed flap of the strip at the outer cylindrical surfaceof the annular heat-insulating body to be exposed to the ambient air forthe evaporation of water transferred from the surface of the tubularbody to the flap of the strip through the strip of the watertransport-allowing material, and

arranging the heat-insulating assembly circumferentially encircling thetubular body so as to arrange the strip of the water transport-allowingmaterial circumferentially encircling the surface of the tubular body,and so as to expose the flap of the strip at the outer cylindricalsurface covered by the vapour-barrier layer for allowing watertransferred from the surface of the tubular body through the watertransport-allowing material of the strip to the flap to be evaporated.

The method according to the second aspect of the present invention mayadvantageously comprise any of the above described features of theheat-insulating assembly according to the first aspect of the presentinvention. Thus, the slit is preferably in accordance with anadvantageous embodiment of the method according to the second aspect ofthe present invention sealed by means of a sealing means which as statedabove may be constituted by a separate water-impermeable adhesivematerial or alternatively a flap of the vapour-barrier layer.

The slit extending through the annular heat-insulating body of theheat-insulating assembly according to the first aspect of the presentinvention and of the heat-insulating assembly to be used in accordancewith the method according to the second aspect of the present inventionmay have any geometrical shape such as a curved configuration providedthe slit extends in the entire length of the annular heat-insulatingbody allowing the annular heat-insulating body to be positionedcircumferentially encirling the tubular body. Preferably, however, theslit is of a rectalinear configuration defining a slit extendinglength-wise along the annular heat-insulating body.

The present invention will now be further described with reference tothe drawings, in which

FIG. 1 is a perspective and schematic view of a first and presentlypreferred embodiment of a heat-insulating assembly to be used forinsulating a pipe or a tubular body, and including a strip of a watertransport-allowing material for the removal of condensed water from theouter surface of the pipe or tubular body, which is insulated by meansof the heat-insulating assembly,

FIGS. 2, 3, and 4 are perspective and schematic views similar to theview of FIG. 1, illustrating three steps of applying the heat-insulatingassembly shown in FIG. 1 to a pipe,

FIG. 5 is a perspective and schematic view similar to the view of FIG. 1of a second embodiment of the heat-insulating assembly according to thepresent invention,

FIGS. 6, 7 and 8 are perspective and schematic view similar to the viewsof FIGS. 2, 3, and 4, respectively, illustrating three steps of applyingthe heat-insulating assembly shown in FIG. 4 to a pipe, and

FIG. 9 is a diagramatic view illustrating the effect of drainingcondensed water from a pipe insulated by means of the heat-insulatingassembly according to the present invention, as compared to the effectof draining condensed water from the same pipes insulated by means ofalternative heat-insulating assemblies.

In FIG. 1, a first and presently preferred embodiment of aheat-insulating assembly according to the present invention is shown,designated the reference numeral 10 in its entirety. The heat-insulatingassembly 10 basically comprises an annular heat-insulating bodyconstituted by a mineral wool body, such as a glass wool, rock wool orslag wool body composed of basically two segments 12 and 14, togetherconstituting the annular heat-insulating body to be arrangedcircumferentially encircling a tubular body, such as a pipe, as will bedescribed in greater details below with reference to FIGS. 2-4. Thesegments 12 and 14 are produced from an annular integral body which iscut lengthwise along a rectilinear slit producing two surfaces 11 and 15to be contacted with one another as the segments 12 and 14 arepositioned circumferentially encircling the above-mentioned tubularbody. The segments 12 and 14 are further separated from one anotherthrough a partial slit 13 extending partly into the wall of the annularheat-insulating body. The slit 13 is preferably produced in the samecutting operation, in which the slit producing the surfaces 11 and 13 isalso produced.

The annular heat-insulating body comprising the segments 12 and 14defines an inner surface, designated the reference numeral 17, whichinner surface in the intentional application of the assembly 10 isarranged juxtaposed the outer surface of the above-mentioned tubularbody. The annular heat-insulating body comprising the segments 12 and 14also defines an outer surface contituting an outer cylindrical surface,as the heat-insulating body comprising the segments 12 and 14 isarranged circumferentially encircling the above-mentioned tubular body.The outer surface of the heat-insulating body is completely covered byan aluminium foil 16, which serves the purpose of providing a vapour andwater barrier preventing vapour and water from permeating into theheat-insulating material of the segments 12 and 14 of theheat-insulating body.

The aluminium covering or foil 16 also comprises a flap 22, whichprotrudes beyond the surface 11 of the segment 12 and which is providedwith an adhesive layer, e.g. an adhesive tape 18, provided with arelease paper 20 and serving the purpose of adhering the flap 22 to thealuminium foil 16 at the surface 15 in overlapping relation.

The heat-insulating assembly 10 further comprises a strip 24 of a watertransport-allowing material, such as a capillary suction material, whichstrip is of a width substantially smaller than the overall length of theheat-insulating body comprising the segments 12 and 14. The strip 24 is,through an end flap 26, adhered to the outer surface of the aluminiumcovering 16 at a position adjacent to the surface 15.

FIGS. 2-4 illustrate three steps of arranging the heat-insulatingassembly 10 relative to a tubular body constituted by a pipe 30, whiche.g. constitutes a cooling pipe of a freezing or refrigerator system orof an air-conditioning system, or a pipe supplying cold water. Thus, thepipe 30, in most instances, serves the purpose of transmitting a fluid,which has a fairly low temperature, at least a temperature which issomewhat lower than the temperature of the ambient air. The fluid maye.g. constitute a cooling or freezing fluid, or cold water.Alternatively, the pipe 30 may constitute a pipe of the type describedin the above-mentioned article.

In order to prevent that the fluid transmitted through the pipe 30 isheated, provided the fluid is a freezing or cooling fluid, theheat-insulating assembly 10 is applied. Initially, the free end of thestrip 24 is positioned within the through-shaped inner space definedwithin the segments 12 and 14 of the heat-insulating body of theheat-insulating assembly 10. Thereafter, the segments 12 and 14 areseparated from one another so as to allow the heat-insulating assembly10 to be positioned circumferentially encircling the outer surface ofthe pipe 30. The heat-insulating assembly 10 is positionedcircumferentially encircling the pipe 30 so as to cause said strip 24 tocontact the outer surface of the pipe 30 for establishing facial contactbetween the strip 24 and the outer surface of the pipe 30, and further,as is evident from FIG. 2, for presenting a flap 28 extending freely outthrough the slit defined between the surfaces 11 and 13.

In the step shown in FIG. 3, the segments 12 and 14 are pressed firmlyagainst one another, causing the surfaces 11 and 13 of the segments 12and 14, respectively, to contact one another, and also causing the slit13 to be closed. Thereupon, the adhesive tape 18 of the flap iscontacted with the outer surface of the aluminium foil 16 of the segment14 adjacent to the above-mentioned slit defined between the surfaces 11and 13 for sealing the slit, after the release paper 20 intitiallycovering the adhesive material of the adhesive tape 20 is removed. Asthe flap 22 is contacted in overlapping relationship with the aluminiumfoil 16 of the segment 14 adjacent to the above-mentioned slit, the flap28 of the strip 24 is exposed in a position overlapping the flap 26.

Finally, as shown in FIG. 4, a perforated adhesive foil 32 is positionedcovering the flaps 26 and 28, still presenting exposed areas of the flap28 to the ambient air through the perforations of the tape

In FIG. 5, a second embodiment of the heat-insulating assembly accordingto the present invention is shown, designated the reference numeral 40in its entirety. The second embodiment 40 differs from theabove-described embodiment 10 in that the second embodiment is composedof a plurality of separate components, whereas the first embodiment 10is a unitary structure to be arranged circumferentially encircling thepipe 30 without the use of additional components apart from theperforated tape 32.

The second embodiment 40 comprises two segments 42 and 44 of an annularheat-insulating body similar to the segments 12 and 14, respectively,described above. The segments 42 and 44 present surfaces 41 and 45similar to the surfaces 11 and 15, respectively, described above, andare further separated through a partial slit 43 similar to the slitdescribed above. The annular heat-insulating body comprising thesegments 42 and 44 presents an inner surface 47 and an outer surface,which is covered by a vapour- and water-impermeable covering 46, such asan aluminium foil.

Whereas the aluminium foil 16 of the first embodiment 10 provided a flap22, the covering 46 solely covers the outer surface of the segments 42and 44 of the annular heat-insulating body without producing any flap.Also, the strip 24 of the first embodiment 10, described above withreference to FIGS. 1-4, is, in the second embodiment 40, substituted bya separate strip 54 of a somewhat larger width. The assembly 40 furthercomprises a length of an adhesive tape 50 provided with a release paper52.

The heat-insulating assembly 40 is arranged in accordance with thetechnique disclosed in FIGS. 6-8. Intitially, the strip 54 is positionedcircumferentially encircling the outer surface of the pipe 30 or,alternatively, positioned within the through-shaped inner space definedwithin the heat-insulating body comprising the segments 42 and 44,whereupon the heat-insulating body is positioned circumferentiallyencircling the outer surface of the pipe 30. As is evident from FIG. 6,the strip 54 presents two flaps 56 and 58 extending out through the slitextending lengthwise through the annular heat-insulating body comprisingthe segments 42 and 44 and defining the surfaces 41 and 45.

Thereupon, the segments 42 and 44, as is evident from FIG. 7, arepressed firmly against the outer surface of pipe 30 in a step similar tothe step described with reference to FIG. 3 for contacting the surfaces41 and 45 with one another, and for closing the slit 43. Similar to thetechnique described above with reference to FIG. 3, the adhesive tape 50is subsequently applied to the outer surface of the covering 46 forsealing the slit defined between the surfaces 41 and 45, and further formaintaining the heat-insulating assembly 40 in the intentional positionshown in FIG. 7. As is evident from FIG. 7, the outer flaps 56 and 58 ofthe strip 54 are exposed to the ambient air at the outer surface of thecovering 46.

In a final step, shown in FIG. 8, a perforated tape 62 similar to thetape 32 is applied to the outer surface of the covering 46 and alsocovering the flaps 56 and 58, still presenting areas of the flap 58 tothe ambient air through the perforations of the perforated tape 52.

The strips 14 and 54 of the above-described first and second embodiments10 and 40, respectively, serve the purpose of draining condensed waterfrom the outer surface of the pipe 30, as the coverings 16 and 46 arenot able to provide hermetic sealing of the annular heat-insulating bodyrelative to the environment and the ambient air. Therefore, moisture orwater may permeate through the heat-insulating material of the annularheat-insulating body of the heat-insulating assembly, causing thedegeneration of condensed water at the outer surface of the pipe 30. Thedegeneration of condensed water at the outer surface of the pipe 30 may,firstly, dependent on the properties and the specific material of theannular heat-insulating body, result in the reduction of the insulatingproperty of the annualar heat-insulating body, as the condensed watermay, in some instances, be absorbed by the material of the annularheat-insulating body and produce an increase of the heat-transportproperties of the material of the annular heat-insulating body, andconsequently reduce the insulating property of the heat-insulatingassembly. Secondly, the condensed water may cause corrosion and/ordeterioration of the pipe 30 and, in some instances, also of thematerial of the annular heat-insulating body of the heat-insulatingassembly. For draining any condensed water from the outer surface of thepipe 30, the strips 14 and 54 are provided in accordance with theteachings of the present invention.

The strips 24 and 54 serve three purposes: firstly, the purpose ofcontacting a surface area of the outer surface of the pipe 30, whicharea is preferably an area positioned at a minimum height above groundlevel, secondly, the purpose of conducting condensed water from the partof the strip contacting the outer surface of the pipe to the flapsexposed at the outer surface of the vapour and water barrier of theheat-insulating assembly, and, thirdly, the purpose of causing condensedwater to evaporate from the flaps exposed to the ambient air.

Contrary to the prior art condensed-water draining technique, theheat-insulating assembly according to the present invention comprises afairly small strip of water transport-allowing material, since it hasbeen realized that the prior art technical solution, as described in theabove-mentioned international patent application, does not functionentirely satisfactory. Thus, it has been realized that the draining andevaporation properties of the prior art structures are somewhatinadequate, since the water transport-allowing material of the prior artstructures, which material covers the overall surface of the pipeinsulated by means of the prior art structures, has to be completelysoaked with water before any evaporation of condensed water from theexposed part of the water transport-allowing material is generated.Thus, the prior art structures unintentionally accumulate a fairly largeamount of water, which inadvertently influences the operation andproperties of the prior art structures.

The above realization is illustrated in FIG. 9, which presents adiagramme illustrating three curves: A, B, and C. The curve Aillustrates the amount of water accumulated within a heat-insulatingassembly implemented in accordance with the above-described first andpresently preferred embodiment 10, which assembly was arrangedcircumferentially encircling a pipe, through which cold water wastransferred. The amount of water accumulated per 1 m of theheat-insulating assembly was determined periodically within a timeperiod of 540 days represented along the abscissa axis of the diagramme.The curve B similarly illustrates the amount of water accumulated per 1m of a heat-insulating structure of the type described in theabove-mentioned international patent application and applied to the verysame pipe as the heat-insulating assembly implemented in accordance withthe teachings of the present invention. The curve C similarlyillustrates the amount of water accumulated per 1 m of a foamedinsulating layer of the type Armaflex™, and also applied to the verysame pipe as the heat-insulating assembly implemented in accordance withthe teachings of the present invention and the heat-insulating structureaccording to the above-mentioned international patent application.

From FIG. 9, it is evident that the heat-insulating assembly implementedin accordance with the teachings of the present invention, so to speak,starts functioning after approximately 40-50 days, as the amount ofwater accumulated within the heat-insulating assembly is fairly constantfrom that time until the end of the test/experiment after 500 days. Theheat-insulating structure according to the above-mentioned internationalpatent application, like the foamed insulating structure, constantlyincreases the amount of water accumulated within the structures forapproximately 200 days, whereupon the heat-insulating structureaccording to the above-mentioned international patent application startsdraining a fairly small amount of water from the pipe, whereas theArmaflex™ heat-insulating structure still increases the amount of wateraccumulated within the heat-insulating structure.

Example 1

A heat-insulating assembly was produced in acordance with the first andpresently preferred embodiment 10, described above with reference toFIGS. 1-4, from the following components: The annular heat-insulatingbody was made from rock wool fibers. The annular heat-insulating bodycomprising the segments 12 and 14 defined an overall length of 50 cm, aninner diameter of 5 cm, and an outer diameter 10 cm. The slits definingthe surfaces 11 and 15, and the slit 13 were positioned diametricallyopposite one another. The annular heat-insulating body was covered by analuminium foil 16 of a thickness of 0.5 mm. The aluminium foil 16defined a flap of a width of 4 cm. The strip 14 of watertransport-allowing material was made from non-woven fleece material andhad a width of 6 cm and a length of 37 cm.

Although the present invention has been described with reference tospecific, presently preferred embodiments of a heat-insulating assemblyand techniques of draining or removing condensed water from the outersurface of a tubular body, such as a pipe, numerous modifications andalternative embodiments are obvious to a person having ordinary skill inthe art. Consequently, the above detailed description is by no means tobe construed limiting the scope of the present invention as defined inthe appending claims. Furthermore, the above embodiments and techniquesare readily combinable in numerous alternatives.

We claim:
 1. A heat-insulating assembly for insulating a surface of atubular body relative to the ambient air, comprising:a length of anannular heat-insulating body defining an inner cylindrical surface andan outer cylindrical surface, a vapour-barrier layer being applied toand covering said outer cylindrical surface of said annularheat-insulating body, and a through-going slit extending through saidannular heat-insulating body in the entire length thereof so as to allowsaid annular heat-insulating body to be opened for positioning saidannular heat-insulating body circumferentially encircling said tubularbody so as to position said inner cylindrical surface juxtaposed saidsurface of said tubular body; and a strip of a water transport-allowingmaterial defining a width substantially smaller than said length of saidannular heat-insulating body and a length allowing said strip to bearranged within said annular heat-insulating body circumferentiallyencircling said tubular body and extending through said slit of saidannular heat-insulating body for presenting an exposed flap of saidstrip at said outer cylindrical surface of said annular heat-insulatingbody to be exposed to the ambient air for the evaporation of watertransferred from said surface of said tubular body to said flap of saidstrip through said strip of said water transport-allowing material. 2.The heat-insulating assembly according to claim 1, said watertransport-allowing material of said strip being a capillary suctionmaterial.
 3. The heat-insulating assembly according to claim 1, saidannular heat-insulating body comprising mineral fibers.
 4. Theheat-insulating assembly according to claims 1, further comprising asealing means for sealing said through-going slit of said annularheat-insulating body.
 5. The heat-insulating assembly according to claim4, said sealing means being constituted by a length of avapour-impermeable adhesive tape.
 6. The heat-insulating assemblyaccording to claim 4, said sealing means being constituted by a flap ofsaid vapour-barrier layer extending along said through-going slit ofsaid annular heat-insulating body and having an adhesive coating foradhering to said vapour-barrier layer in overlapping relationshiptherewith along said through-going slit of said annular heat-insulatingbody.
 7. The heat-insulating assembly according to claim 1, furthercomprising a perforated foil of a vapour-barrier material to be appliedto said vapour-barrier layer covering said exposed flaps of said stripof said water transport-allowing material of said outer cylindricalsurface of said annular heat-insulating body so as to expose said flapof said strip of said water transport-allowing material throughperforations of said perforated foil.
 8. The heat-insulating assemblyaccording to claim 1, said strip defining opposite first and secondends, said first end being adhered to said annular heat-insulating bodyat said through-going slit of said annular heat-insulating body, andsaid second end defining said flap of said strip for the evaporation ofwater transferred from said surface of said tubular body to said flap ofsaid strip through said strip of said water transport-allowing material.9. A method of insulating a surface of a tubular body relative to theambient air and removing condense water from said surface of saidtubular body, comprising:providing a heat-insulating assembly forinsulating said surface of said tubular body, comprising:a length of anannular heat-insulating body defining an inner cylindrical surface andan outer cylindrical surface, a vapour-barrier layer being applied toand covering said outer cylindrical surface of said annularheat-insulating body, and a through-going slit extending through saidannular heat-insulating body in the entire length thereof so as to allowsaid annular heat-insulating body to be opened for positioning saidannular heat-insulating body circumferentially encircling said tubularbody so as to position said inner cylindrical surface juxtaposed saidsurface of said tubular body; and a strip of a water transport-allowingmaterial defining a width substantially smaller than said length of saidannular heat-insulating body and a length allowing said strip to bearranged within said annular heat-insulating body circumferentiallyencircling said tubular body and extending through said slit of saidannular heat-insulating body for presenting an exposed flap of saidstrip at said outer cylindrical surface of said annular heat-insulatingbody to be exposed to the ambient air for the evaporation of watertransferred from said surface of said tubular body to said flap of saidstrip through said strip of said water transport-allowing material; andarranging said heat-insulating assembly circumferentially encirclingsaid tubular body so as to arrange said strip of said watertransport-allowing material circumferentially encircling said surface ofsaid tubular body, and so as to expose said flap of said strip at saidouter cylindrical surface covered by said vapour-barrier layer forallowing water transferred from said surface of said tubular bodythrough said water transport-allowing material of said strip to saidflap to be evaporated.
 10. The method according to claim 9, furthercomprising applying a sealing means of a water-impermeable materialalong said slit for sealing said slit relative to the ambient air. 11.The method according to claim 10, said sealing means being applied as alength of a water-impermeable adhesive tape.
 12. The method according toclaim 10, said sealing means being provided by a flap of saidvapour-barrier layer extending along said slit of said annularheat-insulating body, and said flap being applied along said slit byadhering said flap of said vapour-barrier layer to said vapour-barrierlayer in overlapping relationship therewith along said through-goingslit of said annular heat-insulating body by means of an adhesivecoating applied to said flap of said vapour-barrier layer.
 13. Themethod according to claim 9, further comprising applying a perforatedfoil of a vapour-barrier material to said vapour-barrier layer coveringsaid exposed flaps of said strip of said water transport-allowingmaterial of said outer cylindrical surface of said annularheat-insulating body, so as to expose said flap of said strip of saidwater transport-allowing material through perforations of saidperforated foil.
 14. A heat-insulating assembly for insulating a surfaceof a tubular body relative to the ambient air, comprising:a length of anannular heat-insulating body defining an inner cylindrical surface andan outer cylindrical surface, a vapour-barrier layer being applied toand covering said outer cylindrical surface of said annularheat-insulating body, and a through-going slit extending through saidannular heat-insulating body in the entire length thereof so as to allowsaid annular heat-insulating body to be opened for positioning saidannular heat-insulating body circumferentially encircling said tubularbody so as to position said inner cylindrical surface juxtaposed saidsurface of said tubular body; and a strip of a water transport-allowingmaterial defining a width substantially smaller than said length of saidannular heat-insulating body and a length allowing said strip to bearranged within said annular heat-insulating body circumferentiallyencircling said tubular body and extending through said slit of saidannular heat-insulating body for presenting an exposed flap of saidstrip at said outer cylindrical surface of said annular heat-insulatingbody to be exposed to the ambient air for the evaporation of watertransferred from said surface of said tubular body to said flap of saidstrip through said strip of said water transport-allowing material,wherein the strip of water-transport allowing material is a separatecomponent in relation to the annular heat-insulating body.
 15. Theheat-insulating assembly according to claim 14, said watertransport-allowing material of said strip being a capillary suctionmaterial.
 16. The heat-insulating assembly according to claim 14, saidannular heat-insulating body comprising mineral fibers.
 17. Theheat-insulating assembly according to claim 14, further comprising asealing means for sealing through-going slit of said annularheat-insulating body.
 18. The heat-insulating assembly according toclaim 17, said sealing means being constituted by a length of avapour-impermeable adhesive tape.
 19. The heat-insulating assemblyaccording to claim 17, said sealing means being constituted by a flap ofsaid vapour-barrier layer extending along said through-going slit ofsaid annular heat-insulating body and having an adhesive coating foradhering to said vapour-barrier layer in overlapping relationshiptherewith along said through-going slit of said annular heat-insulatingbody.
 20. The heat-insulating assembly according to claim 14, furthercomprising a perforated foil of a vapour-barrier material to be appliedto said vapour-barrier layer covering said outer cylindrical surface ofsaid annular heat-insulating body so as to expose said flap of saidstrip of said water transport-allowing material through perforations ofsaid perforated foil.
 21. The heat-insulating assembly according toclaim 14, said strip defining opposite first and second ends, said firstend being adhered to said annular heat-insulating body at saidthrough-going slit of said annular heat-insulating body, and said secondend defining said flap of said strip for the evaporation of watertransferred from said surface of said tubular body to said flap of saidstrip through said strip of said water transport-allowing material. 22.A method of insulating a surface of a tubular body relative to theambient air and removing condense water from said surface of saidtubular body, comprising:providing a heat-insulating assembly forinsulating said surface of said tubular body, comprising:a length of anannular heat-insulating body defining an inner cylindrical surface andan outer cylindrical surface, a vapour-barrier layer being applied toand covering said outer cylindrical surface of said annularheat-insulating body, and a through-going slit extending through saidannular heat-insulating body in the entire length thereof so as to allowsaid annular heat-insulating body to be opened for positioning saidannular heat-insulating body circumferentially encircling said tubularbody so as to position said inner cylindrical surface juxtaposed saidsurface of said tubular body; and a strip of a water transport-allowingmaterial defining a width substantially smaller than said length of saidannular heat-insulating body and a length allowing said strip to bearranged within said annular heat-insulating body circumferentiallyencircling said tubular body and extending through said slit of saidannular heat-insulating body for presenting an exposed flap of saidstrip at said outer cylindrical surface of said annular heat-insulatingbody to be exposed to the ambient air for the evaporation of watertransferred from said surface of said tubular body to said flap of saidstrip through said strip of said water transport-allowing material,wherein the strip of water-transport allowing material is a separatecomponent in relation to the annular heat-insulating body; and arrangingsaid heat-insulating assembly circumferentially encircling said tubularbody so as to arrange said strip of said water transport-allowingmaterial circumferentially encircling said surface of said tubular body,and so as to expose said flap of said strip at said outer cylindricalsurface covered by said vapour-barrier layer for allowing watertransferred from said surface of said tubular body through said watertransport-allowing material of said strip to said flap to be evaporated.23. The method according to claim 22 further comprising applying asealing means of a water-impermeable material along said slit forsealing said slit relative to the ambient air.
 24. The method accordingto claim 23, said sealing means being applied as a length of awater-permeable adhesive tape.
 25. The method according to claim 23,said sealing means being provided by a flap of said vapour-barrier layerextending along said slit of said annular heat-insulating body, and saidflap being applied along said slit by adhering said flap of saidvapour-barrier layer to said vapour-barrier layer in overlappingrelationship therewith along said through-going slit of said annularheat-insulating body by means of an adhesive coating applied to saidflap of said vapour-barrier layer.
 26. The method according to claim 22,further comprising applying a perforated foil of a vapour-barriermaterial to said vapour-barrier layer covering said outer cylindricalsurface of said annular heat-insulating body, so as to expose said flapof said strip of said water transport-allowing material throughperforations of said perforated foil.
 27. A heat-insulating assembly forinsulating a surface of a tubular body relative to the ambient air,comprising:a length of an annular heat-insulating body defining an innercylindrical surface and an outer cylindrical surface, a vapour-barrierlayer being applied to and covering said outer cylindrical surface ofsaid annular heat-insulating body, and a through-going slit extendingthrough said annular heat-insulating body in the entire length thereofso as to allow said annular heat-insulating body to be opened forpositioning said annular heat-insulating body circumferentiallyencircling said tubular body so as to position said inner cylindricalsurface juxtaposed said surface of said tubular body; and a strip of awater transport-allowing material defining a width substantially smallerthan said length of said annular heat-insulating body and a lengthallowing said strip to be arranged within said annular heat-insulatingbody circumferentially encircling said tubular body and extendingthrough said slit of said annular heat-insulating body for presenting anexposed flap of said strip at said outer cylindrical surface of saidannular heat-insulating body to be exposed to the ambient air for theevaporation of water transferred from said surface of said tubular bodyto said flap of said strip through said strip of said watertransport-allowing material, wherein the strip of water-transportallowing material has one end fixated to the heating-insulating body ata position adjacent to the through-going slit.
 28. A method ofinsulating a surface of a tubular body relative to the ambient air andremoving condense water from said surface of said tubular body,comprising:providing a heat-insulating assembly for insulating saidsurface of said tubular body, comprising:a length of an annularheat-insulating body defining an inner cylindrical surface and an outercylindrical surface, a vapour-barrier layer being applied to andcovering said outer cylindrical surface of said annular heat-insulatingbody, and a through-going slit extending through said annularheat-insulating body in the entire length thereof so as to allow saidannular heat-insulating body to be opened for positioning said annularheat-insulating body circumferentially encircling said tubular body soas to position said inner cylindrical surface juxtaposed said surface ofsaid tubular body; and a strip of a water transport-allowing materialdefining a width substantially smaller than said length of said annularheat-insulating body and a length allowing said strip to be arrangedwithin said annular heat-insulating body circumferentially encirclingsaid tubular body and extending through said slit of said annularheat-insulating body for presenting an exposed flap of said strip atsaid outer cylindrical surface of said annular heat-insulating body tobe exposed to the ambient air for the evaporation of water transferredfrom said surface of said tubular body to said flap of said stripthrough said strip of said water transport-allowing material, whereinthe strip of water-transport allowing material has one end fixated tothe heating-insulating body at a position adjacent to the through-goingslit; and arranging said heat-insulating assembly circumferentiallyencircling said tubular body so as to arrange said strip of said watertransport-allowing material circumferentially encircling said surface ofsaid tubular body, and so as to expose said flap of said strip at saidouter cylindrical surface covered by said vapour-barrier layer forallowing water transferred from said surface of said tubular bodythrough said water transport-allowing material of said strip to saidflap to be evaporated.
 29. The heat-insulating assembly according toclaim 27, said water transport-allowing material of said strip being acapillary suction material.
 30. The heat-insulating assembly accordingto claim 27, said annular heat-insulating body comprising mineralfibers.
 31. The heat-insulating assembly according to claim 27, furthercomprising a sealing means for sealing through-going slit of saidannular heat-insulating body.
 32. The heat-insulating assembly accordingto claim 1, said sealing means being constituted by a length of avapour-impermeable adhesive tape.
 33. The heat-insulating assemblyaccording to claim 31, said sealing means being constituted by a flap ofsaid vapour-barrier layer extending along said through-going slit ofsaid annular heat-insulating body and having an adhesive coating foradhering to said vapour-barrier layer in overlapping relationshiptherewith along said through-going slit of said annular heat-insulatingbody.
 34. The heat-insulating assembly according to claim 27, furthercomprising a perforated foil of a vapour-barrier material to be appliedto said vapour-barrier layer covering said exposed flaps of said stripof said water transport-allowing material of said outer cylindricalsurface of said annular heat-insulating body so as to expose said flapof said strip of said water transport-allowing material throughperforations of said perforated foil.
 35. The heat-insulating assemblyaccording to claim 27, said strip defining opposite first and secondends, said first end being adhered to said annular heat-insulating bodyat said through-going slit of said annular heat-insulating body, andsaid second end defining said flap of said strip for the evaporation ofwater transferred from said surface of said tubular body to said flap ofsaid strip through said strip of said water transport-allowing material.36. The method according to claim 28, further comprising applying asealing means of a water-impermeable material along said slit forscaling said slit relative to the ambient air.
 37. The method accordingto claim 36, said sealing means being applied as a length of awater-permeable adhesive tape.
 38. The method according to claim 36,said sealing means being provided by a flap of said vapour-barrier layerextending along said slit of said annular heat-insulating body, and saidflap being applied along said slit by adhering said flap of saidvapour-barrier layer to said vapour-barrier layer in overlappingrelationship therewith along said through-going slit of said annularheat-insulating body by means of an adhesive coating applied to saidflap of said vapour-barrier layer.
 39. The method according to claim 28,further comprising applying a perforated foil of a vapour-barriermaterial to said vapour-barrier layer covering said exposed flaps ofsaid strip of said water transport-allowing material of said outercylindrical surface of said annular heat-insulating body, so as toexpose said flap of said strip of said water transport-allowing materialthrough perforations of said perforated foil.